Inner-tube patch



Patented Apr. 29, -1er-ie,l

UNITEDv STATES PATENT 'OFFICE CLARENCE E. DUNLAP, 0F SIOUX CITY, IOWA INNER-TUBE PATCH Application iled Janualy 7, 1929. Serial No.7330,820.

My invention relates to tube patches of the preformed type, that is, the type in which individual patches oth round or square shape are cut or shaped in the factory and so as to be ready for immediate use onbeingvremoved from their package.

My invention further relates to a preformed patch ofthe type having a layer c-t' uncured rubber for adhesion to the surface of an inner tube. a layer of protective fabric covering the face ot" said uncured layer and av layer or layers o't cured rubber forming a backing for the layer, of uncured rubber.

My invention inrther relates to a preformed patch ot' the above described variety having itsedges or edge bevelled in order to render the patch more secure against peeling after it has adhered to the surface of a tube.

The purpose of my invention is to provide a patch ofthe above mentioned type in which the layer of uncured rubber will bel protected for a maximum length of time against drying out or air curing.

More particularly, it is my object to provide such a patch in which the uncured layer is protected from drying ont from above.

'ith these. and other objects in view, my invention consists in the constrnctimi. arrangement' aml combination of the various partso't my device. whereby the objects contemplated alv attained, as*hereinafter more fully set forth. pointed ont in my claim, and illustrated in the accompanying drawings. in which Fig. 1 is a plan view of a patch embodying my invention.

Fig. 2 is an enlarged, sect ional view through one edge of the, patch.

Fig. 3 is a similar sectional view' through the patch adhering to an inner tube.

I have used the reference character l0 to indicate the layer of nneured rubber of the patch.' The adhesive face of this layer is protected by fabric l1 and the opposite face is yunited with a layer of cured rubber l2.

The patch illustrated which is the vpatch sold commercially is in actuality a four-ply patch, thc upper layer 13 being a thick layer and substantially twice the thickness of the laVcI' l2. l

My invention consists in forming' the patch with a bevel tft. and a square cut l5, which meets the bevel lt at about the center of thickness of the layer l2. Thus` a very thin but substantial shoulder ot' cured rubber vis formed to completel)7 cover from above the layer l() ot uncured rubber. This shoulder is indicated in the drawings by the reference character 1G.

In that type otl patch in which the bevel is carried entirely to the adhesive face ot the. uncured layer. the adhesive layer will dry ont from above, owing to the extreme thinness of thematerial at the edge of the patch. In my patch, the only exposure of the uncured layer of rubber is at the edge and since thisl edge is perpendicular. itis of minimum area as compared with a bevelled face.

"When the patch is united with a tube, the layer ot u'ncured rubber is absorbed into the material ot' the tube so as to leave only the shoulder lt projecting from the surface of tbe tube. l rl`his is illustrated iny Fig. 5%. Thus only` tbe ver)` narrow width of the shoulder 1G will be lett projecting above the tube. after the patch is in place. The etiectiveness of the bevelled t'ace l-t. in protecting the. patch against'. peeling wiil no! be impaired by this projecting shoulder.` The tube is indicated by the reference character 1T.

Home changes may be made in the const rueVA 'tion and arrangement ot' the parts ot my invention without. departing from the real spirit and purpose ot my invention. and it is my intention to cover b v my claim, any modified forms of structure or use of mechanical equivalents, which may be reasonably included within their scope, l

I claim as my invention:

An inner tube patch of' preformed shape.y comprising' a layer of unenred rubber, a laye;

of protective fabric .adhering to the adhesiveA till' kim face thereof, and a layer of cured rubber united with the rear face thereof, the ledge, of the Cured layer being bevelied through a majority of its thickness, andthe remainder of its thickness4 together with all of' the un- Cured iayer and the fabric, being eut @if squarely to leave a shoulder of cured rubber emnpietely covering the rear face of the, uneiu'ed layer.

Signed this 29th day of December, 1928, in the eimnfy of \Y )odbury and State of Iowa.

CLARENCE E. DUJLAP. 

